Opening nt 3.1 pe32 files results in the following warning,

And the import/export tabs are missing.
This happens with all the nt 3.1 executables and dlls in the SYSTEM32 folder (that I've tested), including NOTEPAD.EXE.
These executables are able to be ran on the latest version of Windows (they are the same executable type) and the imports/exports appear in programs like ida.

PE-bear version: v0.6.7.3